We all may have heard the name of CD4 cells. They are familiar to us by different names, however. We generally know them as T-lymphocytes or T-cells that play a very important role in the functionality of our immune system. Our thymus gland generates them. These cells circulate throughout our entire bloodstream and lymphatic system. CD4 test is to measure the total number of the cells in our blood and in conjunction with an HIV viral load test, it’s useful for identifying the immune system condition in a person having (or suspected to have) HIV infection.

What is it used for?

A CD4 count may be helpful in the following conditions –

Find out how HIV is affecting the immune system. This helps the healthcare provider to find out the risks relating to other diseases and similar complications.

Decide whether the doctor needs to change to the HIV medicine(s).

Diagnose AIDS (Acquired Immunodeficiency Syndrome).
Both the names AIDS and HIV describe the same disease. However, most of the people having HIV doesn’t have AIDS. When the CD4 count is extremely low, only then the patient will be diagnosed for AIDS.

AIDS is the most severe form that arrives after being infected with HIV. In this stage, the immune system is in really bad shape and such condition is suitable for other opportunistic germs. These are, often times, serious and life-threatening.

You may also need a CD4 count test if you had to undergo an organ transplant. Organ transplant patients require special medicines to suppress the immune system so that it won’t attack the alien organ. In such a situation, a lower CD4 count is a good sign. It also indicates that the medicines are working properly.

Why do you need CD4 Count Test?

The CD4 count test is more like a snapshot of the immune system – how well it’s functioning. CD4 cells (aka CD4+ T cells) are white blood cells that fight against mostly harmful objects. Generally, the more CD4 count, the better. These are the cells that are capable of killing the HIV virus! As HIV infection progresses, the number of CD4 cells continue to decrease. When the CD4 count is below 200, a person must be diagnosed with AIDS. The normal range of CD4 count is 500 to 1,200. Usually, the count of CD4 increases when the HIV virus is under control with the help of effective HIV treatments.

What do the results mean?

CD4 results are the number of CD4 cells per cubic millimeter of blood. Here is a list of typical results. Depending on your health and even lab test method, the result may vary. For any question relating to the result, you should consult your healthcare provider.

Normal: If the count is 500–1,200 cells per cubic millimeter, it’s normal.

Abnormal: 250–500 cells per cubic millimeter. It indicates a weakened immune system and possibly has been infected with HIV.

Abnormal: If the count is 200 or less per cubic centimeter. It indicates AIDS and indicates life-threatening opportunistic infections.

There’s no cure for HIV infection yet. However, there are a number of medicines that can protect the immune system and prevent getting weaker and develop AIDS. Now, people with HIV are living longer with a better quality of life. If you were infected with HIV, it’s important that you regularly consult your healthcare provider.

Test Preparation

There’s no test preparation necessary. This test requires only a small amount of blood sample from the vein of your arm.

Is there anything else I should know?

Generally, the CD4 count tends to be lower in the morning and higher in the evening. If you’re suffering from the acute illness like influenza, herpes simplex virus infection or pneumonia etc. the count of CD4 may decline temporarily. Cancer chemotherapy is also responsible for drastically changes in the CD4 count.

CD4 count isn’t the full picture that shows how someone with HIV feels and functions. For example, people with higher counts may be ill and face frequent complications and some with lower CD4 counts facing fewer complications and functioning properly.

The Centers for Disease Control and Prevention considers people having HIV infection and CD4 count below 200 cells/mm­­3 to have AIDS (state III HIV infection) irrespective to whether there’s any sign or symptoms of the disease.